TMC used trucks

It doesnt really matter that its a tmc truck other than the fact that they probably use extended oil changes. Any fleet does that anyways. I would look very carefully at the engine history for updates or rebuilds etc. A lot of those isx never made 400k without needing a rebuild. Most of those were done under warranty. You wont have that luxury. A friend bought a 13? with around 400k on it. He's had to dump close to 30 into it in 2 years. Most of the stuff wasn't due to the previous owner neglect. Just wear and tear. Was down last week for a day. Minimum 1000 dollar bill. Really really look over the history at Cummins. He likes the engine but that's a lot of money into a 5 year old 500k truck with no real end in sight.

 

Doing a dyno on a engine with around a million miles what could possibly go wrong ?

 

Op what's the mileage on that truck?

 

Definitely find out if it has had an engine replacement; I wouldn't touch it if has. The stealership would have only replaced any defective parts and not the ones that might have recieved partial damage or accelerated wear.

 

My bad...
Good luck to you Sir..